P wave analysis with wavelets identifies hypertensive patients at risk of recurrence of atrial fibrillation: A case-control study and 1 year follow-up

•Wavelet analysis of ECG signals is a non-invasive, inexpensive and easy to apply method, which was reported predictive of AF recurrences in patients without structural heart disease and in those with hypertrophic cardiomyopathy; P wave wavelet analysis was never studied before in hypertensive patients with recent onset paroxysmal AF.•Wavelet analysis identified with sufficient accuracy AF patients after successful pharmacological cardioversion from an otherwise identical cohort of hypertensive patients with no history of AF at baseline.•Hypertensive patients with more pronounced derangements in atrial impulse formation and propagation - reflected by P waves that are longer in duration and carrying a higher mean energy as shown by wavelet analysis - experienced a significantly decreased AF-free survival during follow-up.•Unmasking wavelet components hidden within the high voltage amplitude P waves of the surface ECG can potentially serve as screening tool to identify hypertensive patients at risk of future AF episodes.

AimsHypertension is a major risk factor for atrial fibrillation (AF); however, reliable non-invasive tools to assess AF risk in hypertensive patients are lacking. We sought to evaluate the efficacy of P wave wavelet analysis in predicting AF risk recurrence in a hypertensive cohort.MethodsWe studied 37 hypertensive patients who presented with an AF episode for the first time and 37 age- and sex-matched hypertensive controls without AF. P wave duration and energy variables were measured for each subject [i.e. mean and max P wave energy along horizontal (x), coronal (y) and sagittal (z) axes in low, intermediate and high frequency bands]. AF-free survival was assessed over a follow-up of 12.1 ± 0.4 months.ResultsP wave duration (Pdurz) and mean P wave energy in the intermediate frequency band across sagittal axis (mean2z) were independently associated with baseline AF status (p = 0.008 and p = 0.001, respectively). Based on optimal cut-off points, four groups were formed: Pdurz < 83.2 ms/mean2z < 6.2 μV2 (n = 23), Pdurz < 83.2 ms/mean2z ≥ 6.2 μV2 (n = 10), Pdurz ≥ 83.2 ms/mean2z < 6.2 μV2 (n = 22) and Pdurz ≥ 83.2 ms/mean2z ≥ 6.2 μV2 (n = 19). AF-free survival decreased (Log Rank p < 0.0001) from low risk (Pdurz < 83.2 ms/mean2z < 6.2 μV2) to high-risk group (Pdurz ≥ 83.2 ms/mean2z ≥ 6.2 μV2). Patients presenting with longer and higher energy P waves were at 18 times higher AF risk compared to those with neither (OR: 17.6, 95% CI: 3.7-84.3) even after adjustment for age, sex, hypertension duration, left atrial size, beta-blocker, ACEi/ARBs and statin therapy.ConclusionsP wave temporal and energy characteristics extracted using wavelet analysis can potentially serve as screening tool to identify hypertensive patients at risk of AF recurrence.